Embodiments of the invention relate generally to integrated circuit chip packages and, more particularly, to chip package build-up. Chip packages are manufactured using a technique that protects the die from contamination during a build-up process of the chip package.
Integrated circuit (IC) chip packages are typically fabricated to include one or more dies that are attached to a laminate re-distribution layer. The laminate re-distribution layer is comprised of a dielectric laminate material, such as Kapton®, and is affixed to the die by way of an adhesive layer. The die(s) are electrically connected to an input/output system by way of metal interconnects routed through a plurality of additional laminate re-distribution layers that are adhered to the base re-distribution layer.
A standard chip package manufacturing or build-up process typically begins with providing of the base laminate re-distribution layer and application of an adhesive on one surface thereof. The one or more dies are then secured relative to the base laminate re-distribution layer by applying a front or active face of the die(s) onto the adhesive layer such that a bond is formed between the active face of the die(s) and the adhesive layer across the full face of the die(s). Metal interconnects are then formed and routed through the base laminate re-distribution layer and through any additional laminate re-distribution layers that are subsequently added during build-up of the chip package.
Deposition of the die(s) onto the base re-distribution layer in this manner, however, has inherent limitations in regards to the production process and the structure and functionality of the resulting chip package that is produced. That is, in some applications it is desirable that the active face of the die(s) be protected from possible contamination during the build-up process of the chip package. For example, for application of the chip package in an imaging device such as an ultra camera or similar sensing device, it is desired that the imager area (i.e., the die) be protected from contamination during the build-up process. As the imager area/die in such an application is to be left exposed upon completion of the build-up of the chip package, it is undesirable for a bond to be formed between the active face of the die and the adhesive layer across the full face of the die during the build-up process. Such a build-up would require subsequent removal of the adhesive from the imaging area and could introduce contaminates to the imaging area, thereby negatively affecting the performance of the ultra camera/sensing device.
Accordingly there is a need for a method for chip package fabrication that protects the die from contamination during the build-up process. There is a further need for the fabrication method to be readily incorporated into an assembly process, be compatible with laser drilling, be scalable, and provide for a low cost assembly.